1. Field of the Invention
The present invention relates to a method for the evaluation of radar data for fully automatic creation of a map of regions with interference.
2. The Prior Art
In methods for the evaluation of radar signals, the problem occurs that in addition to the desired echoes from ships and aircraft (true targets), a great number of undesirable reflections are also received. These undesirable reflections include reflections from waves, the ground, clouds, windmills, cars or the like (false targets). In the creation of a position image in which the echoes that belong to a target, in each instance, are joined together to form a target track from the various revolutions of the antenna, so-called false tracks result from the undesirable reflections. These disrupt the otherwise stable position image, confuse the operator, and can thus result in incorrect decisions. The problem is all the more serious as the required initiation time, in other words the time that is allowed to elapse from the first echo to the presentation of a target track on the screen, becomes shorter.
Modern radar systems attempt to suppress false tracks even in the case of short initiation times, by accessing various maps on which regions with interference are shown. For this purpose, a special treatment is performed in regions such as roads or wind farms. For example, this special treatment may consist of a prohibition against initiation. Such methods are described, for example, in the publication of the study: Feasibility of mitigating the effects of wind farms on primary radar, ETSU W/14/00623/REP, DTI (Department of Trade and Industry) UK, PUB URN No. 03/1976, 2003.
The known radar evaluation methods with special consideration of regions with interference have one or more of the following disadvantages:
The map information must be input and updated manually.
They are based exclusively on the analysis of individual echoes and also include those regions in which desirable echoes occur with greater frequency. These are, for example, flight paths and ocean routes, in which reliable initiation is particularly important.
They have a negative influence on the discovery likelihood of the system, which is unacceptable for military uses.
They are connected with significant technical and financial expenditure.